The interface theory of consciousness suggests that the physical world which we inhabit is not in fact reality. The world is not material. The true essence of reality is sensory experience. The brain, in order to experience physical reality, must form a physical representation of sensory inputs, which the brain has to interpret in order to arrive at the ultimate meaning or meaning that it then interprets for the final outcome of an action.
The theory also suggests that all material objects, including the bodies of all living creatures, are merely objects of sensory experience. When physical objects are perceived by an organism, their meaning is perceived in terms of a physical representation of their physical properties. If there is a difference in the actual physical properties of a material object, a physical object has a meaning, or, if there is no difference, their meaning of that object will not be determined to any level of accuracy. The meaning of a material object may then be a subjective interpretation of that object’s sensory meaning, without any objective foundation or meaning in the physical world. It’s only as objects and events are interpreted by our brain that the physical properties are finally perceived, and this physical interpretation, for all intents and purposes, defines our physical reality.
According to the second theory of mind, what makes us individuals is not that our brains are our bodies, or that our bodies are our brains. What makes us individuals is the way in which we experience physical reality. In short, our physical reality is not only defined by the objects we perceive, as we saw here. Our sensory input, which is the input that our brain experiences, is the definition of physical reality. And what the brain experiences in order to interpret that input as meaning, in the end, defines our physical reality.
This theory of minds also does not posit that what makes us humans is the physical attributes of our bodies. Rather, it is the way that our bodies are constituted that determines our reality, in ways which are not only objective, in terms of their physical properties, but very much subjective, because we perceive ourselves differently based upon the way in which our minds conceptualize our experience. So, these philosophies differ quite significantly.
Which is the correct approach to take? I would argue, as it relates to the philosophical basis of consciousness theory, that the physicalist approach is correct for one very important reason. Physicalist approaches to the theory of mind also have advantages for our scientific understanding of that theory. And, if the physicalist approach is correct, then we can now begin to study the neural processes which have the capacity to define subjective experience, rather than the subjective interpretation of that experience. This approach to the theory of mind will not only help us explain what it’s like to be human, it will also provide us with a powerful model for explaining what happens in the brain when we are in a state of sleep.